Steric structure of L-proline oligopeptides. II. Far-ultraviolet absorption spectra and optical rotations of L-proline oligopeptides

The results of the measurement of the far-ultraviolet absorption spectra of L -proline oligomers in water and acetonitrile are summarized as follows. The monomer has an absorption maximum at 182.5 mμ in acetonitrile. The absorption maximum of the dimer is found at 185 mμ and a shoulder appears around 200 mμ, that is, splitting of the absorption spectrum is observed in the dimer. As the degree of polymerization increases, the position of the shoulder shifts toward the wavelength of the absorption maximum of poly-L -proline II, with an accompanying increase in intensity. We may describe the absorption peak around 203 mμ of poly-L -proline II as identical with the shoulder with an increased intensity. By measurements of optical rotatory dispersion and circular dichroic spectra, it was also confirmed that the appearance of the helical conformation commences at the tetramer. When the number of residues is five or greater, the conformation of the helical structure of poly-L -proline II seems to be completed.     

Chloroplast Development in the Chloroplast Ribosome Deficient Mutant (y-1 ac-20) of Chlamydomonas reinhardtii

To study the participation of chloroplast protein synthesisduring the three phases [Matsuda (1974) Biochim. Biophys. Acta366:45] of the greening process in Chlamydomonas reinhardtiiy-1, the greening characteristics in the low-chloroplast ribosomemutant y-1 ac-20 were compared with those in the y-1. In thedouble mutant cells Chl synthesis proceeded with an extendedlag and without a second transition point. The development ofpotential for rapid Chl synthesis (P-factor formation) was alsodelayed. Furthermore, PS I activity increased significantly,whereas PS II activity developed very little during greeningof the double mutant cells. The results indicate that greeningin double mutant cells occurs with no apparent late phase. (Received November 26, 1984; Accepted February 25, 1985)     

Expression of Epidermal Growth Factor Receptor Detected by Cetuximab Indicates Its Efficacy to Inhibit In Vitro and In Vivo Proliferation of Colorectal Cancer Cells

Cetuximab is a chimeric mouse–human monoclonal antibody that targets the human epidermal growth factor receptor (EGFR). However, EGFR expression determined by immunohistochemistry does not predict clinical outcomes of colorectal cancer (CRC) patients treated with cetuximab. Therefore, we evaluated the correlation between EGFR levels detected by cetuximab and drug sensitivities of CRC cell lines (Caco-2, WiDR, SW480, and HCT116) and the A431 epidermoid carcinoma cell line. We used flow cytometry (FCM) to detect EGFR-binding of biotinylated cetuximab on the cell surface. Subcloned cell lines showing the highest and lowest EGFR expression levels were chosen for further study. Cytotoxic assays were used to determine differential responses to cetuximab. Xenograft models treated with cetuximab intraperitoneally to assess sensitivity to cetuximab. Strong responses to cetuximab were specifically exhibited by subcloned cells with high EGFR expression levels. Furthermore, cetuximab inhibited the growth of tumors in xenograft models with high or low EGFR expression levels by 35% and 10%–20%, respectively. We conclude that detection of EGFR expression by cetuximab promises to provide a novel, sensitive, and specific method for predicting the sensitivity of CRC to cetuximab.     

Enhancement of Glossiness Perception by Retinal-Image Motion: Additional Effect of Head-Yoked Motion Parallax

It has been argued that when an observer moves, a contingent retinal-image motion of a stimulus would strengthen the perceived glossiness. This would be attributed to the veridical perception of three-dimensional structure by motion parallax. However, it has not been investigated whether the effect of motion parallax is more than that of retinal-image motion of the stimulus. Using a magnitude estimation method, we examine in this paper whether cross-modal coordination of the stimulus change and the observer''s motion (i.e., motion parallax) is essential or the retinal-image motion alone is sufficient for enhancing the perceived glossiness. Our data show that a retinal-image motion simulating motion parallax without head motion strengthened the perceived glossiness but that its effect was weaker than that of motion parallax with head motion. These results suggest the existence of an additional effect of the cross-modal coordination between vision and proprioception on glossiness perception. That is, motion parallax enhances the perception of glossiness, in addition to retinal-image motions of specular surfaces.     

Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis

BackgroundAlthough several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.ObjectiveThe purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.MethodsA total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from −950 HU to −701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.ResultsCT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).ConclusionThe measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.     

Large-scale profiling of brown rice ionome in an ethyl methanesulphonate-mutagenized hitomebore population and identification of high- and low-cadmium lines

Background and aim

Recycled sources of phosphorus (P), such as struvite extracted from wastewater, have potential to substitute for more soluble manufactured fertilisers and help reduce the long-term threat to food security from dwindling finite reserves of phosphate rock (PR). This study aimed to determine whether struvite could be a component of a sustainable P fertiliser management strategy for arable crops.

Methods

A combination of laboratory experiments, pot trials and mathematical modelling of the root system examined the P release properties of commercial fertiliser-grade struvite and patterns of P uptake from a low-P sandy soil by two different crop types, in comparison to more soluble inorganic P fertilisers (di-ammonium phosphate (DAP) and triple super phosphate (TSP)).

Results

Struvite had greatly enhanced solubility in the presence of organic acid anions; buckwheat, which exudes a high level of organic acids, was more effective at mobilising struvite P than the low level exuder, spring wheat. Struvite granules placed with the seed did not provide the same rate of P supply as placed DAP granules for early growth of spring wheat, but gave equivalent rates of P uptake, yield and apparent fertiliser recovery at harvest, even though only 26 % of struvite granules completely dissolved. Fertiliser mixes containing struvite and DAP applied to spring wheat have potential to provide both optimal early and late season P uptake and improve overall P use efficiency.

Conclusions

We conclude that the potential resource savings and potential efficiency benefits of utilising a recycled slow release fertiliser like struvite offers a more sustainable alternative to only using conventional, high solubility, PR-based fertilisers.

     

Skp2 controls adipocyte proliferation during the development of obesity

The increase in the mass of adipose tissue during the development of obesity can arise through an increase in cell size, an increase in cell number, or both. Here we show that long term maintenance of C57BL/6 mice on a high fat diet (for approximately 25 weeks) induces an initial increase in adipocyte size followed by an increase in adipocyte number in white adipose tissue. The latter effect was found to be accompanied by up-regulation of expression of the gene for the F-box protein Skp2 as well as by downregulation of the cyclin-dependent kinase inhibitor p27(Kip1), a principal target of the SCF(Skp2) ubiquitin ligase, in white adipose tissue. Ablation of Skp2 protected mice from the development of obesity induced either by a high fat diet or by the lethal yellow agouti (A(y)) mutation, and this protective action was due to inhibition of the increase in adipocyte number without an effect on adipocyte hypertrophy. The reduction in the number of adipocyte caused by Skp2 ablation also inhibited the development of obesity-related insulin resistance in the A(y) mutant mice, although the reduced number of beta cells and reduced level of insulin secretion in Skp2-deficient mice resulted in glucose intolerance. Our observations thus indicate that Skp2 controls adipocyte proliferation during the development of obesity.     

Biochemical characterization of photosystem I complexes having different subunit compositions of fucoxanthin chlorophyll a/c-binding proteins in the diatom Chaetoceros gracilis

Photosynthesis Research - Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom...